Explosive DetonatorPre-1917Donated by Paul Labas2005.004.0002

This detonator is marked on the bottom with “Big Boston Quarry,” located in West Pawlet, Vermont. The front metal plate reads “Maintenance Instructions” and is consistent with the style of portable electric generators used for blasting stone. It was manufactured by E. I. duPont de Nemours & Company (DuPont), established in 1802, in Wilmington, Delaware.DuPont detonators came in six (6) sizes or models. The detonator displayed here is believed to be a Model 3 because it has a magneto that fires 10 to 30 electric blasting caps. After blasting caps are set in place and wired, the charge is set off by a swift downward movement of the plunger that protrudes from the top. This sets the armature and pinion gear on a magneto shaft in motion to create an electric charge. This type of electric detonator was invented by H. Julius Smith in 1878.

​In Sweet’s Engineering Catalog: 1915 there is a description of the types of blasting power, “A” based on potassium nitrate or “B” based upon sodium nitrate. Type “A” is described as best for use within quarries (granite, limestone, and slate) where “the work is damp, and where a quicker acting explosive … is desired.”